The incoherence of the dream seems to me easy enough to explain. As it is characteristic of the dream not to demand a complete adjustment between the memory image and the sensation, but, on the contrary, to allow some play between them, very different memories can suit the same sensation. For example, there may be in the field of vision a green spot with white points. This might be a lawn spangled with white flowers. It might be a billiard-table with its balls. It might be a host of other things besides. These different memory images, all capable of utilizing the same sensation, chase after it. Sometimes they attain it, one after the other. And so the lawn becomes a billiard-table, and we watch these extraordinary transformations. Often it is at the same time, and altogether that these memory images join the sensation, and then the lawn will be a billiard-table. From this come those absurd dreams where an object remains as it is and at the same time becomes something else. As I have just said, the mind, confronted by these absurd visions, seeks an explanation and often thereby aggravates the incoherence. As for the abolition of the sense of time in many of our dreams, that is another effect of the same cause. In a few seconds a dream can present to us a series of events which will occupy, in the waking state, entire days. You know the example cited by M. Maury: it has become classic, and although it has been contested of late, I regard it as probable, because of the great number of analogous observations that I found scattered through the literature of dreams. But this precipitation of the images is not at all mysterious. When we are awake we live a life in common with our fellows. Our attention to this external and social life is the great regulator of the succession of our internal states. It is like the balance wheel of a watch, which moderates and cuts into regular sections the undivided, almost instantaneous tension of the spring. It is this balance wheel which is lacking in the dream. Acceleration is no more than abundance a sign of force in the domain of the mind. It is, I repeat, the precision of adjustment that requires effort, and this is exactly what the dreamer lacks. He is no longer capable of that attention to life which is necessary in order that the inner may be regulated by the outer, and that the internal duration fit exactly into the general duration of things.